Recently, as the number of various moving objects such as motor vehicles and the like increase, traffic congestion continues to increase. Specifically, the number of motor vehicles is increasing considerably faster than the corresponding growth in the necessary infrastructure. Navigation systems are being incorporated into motor vehicles as one of the solutions for offsetting traffic congestion.
A typical navigation system detects a current object position using navigation messages transmitted from a plurality of GPS (global positioning system) satellites and moving object drive state detecting signals detected by a plurality of sensors provided on the corresponding moving objects such as a gyroscope, a speed sensor and the like. If a current position of the moving object is detected, the detected current position of the moving object is matched to map data. The current position of the moving object is then displayed on a display unit together with a corresponding map.
The navigation system provides the functionality of searching a drive path of a moving object from an origination to a destination using the map data, and the functionality of guiding the drive path to enable the moving object to drive along the searched drive path.
If the moving object is driving along the searched drive path, the navigation system searches prescribed guide targets in front of the moving object, such as an intersection, an underpass, an overpass, a highway entrance/exit and the like. If the moving object approaches the searched guide target within a prescribed distance, the navigation system guides the drive path via a voice signal and the like.
The navigation system determines if the moving object deviates from the searched drive path and drives along another, different path. The navigation system informs a user of any deviation from the drive path to enable the user to correctly maneuver the moving object along the drive path. Therefore, the drive path of the moving object is searched and guided so that the given road system can be efficiently utilized.
In the above-explained navigation system, information relating to a perimeter area of the moving object is displayed on a map showing the perimeter area about a current location of the moving object on a display unit. The information relating to the perimeter area is provided by appropriately arranging topographical information of the perimeter area, major points, major building names, road information, road names and the like on the map to display.
The map is generated by horizontally arranging the topographical information, major points, major building names and the like so that a user can simply check them out. However, if the names of all of the roads and other landmarks are horizontally displayed, the names of the roads and landmarks may overlap.
In a typical navigation system, the road names are generally displayed parallel to the corresponding links. However, in the conventional navigation system, a cartographer making the map has to determine the positions of the road names individually, thereby requiring an inefficient and resource intensive effort.